Fen Management Handbook - Scottish Natural Heritage

are realised. In these cases, an ‘artificial’ interim solution might be needed, and
routine monitoring should be continued long-term.
Always consider how any action you take to alter water levels on a fen might impact
on surrounding land, for example drainage of adjacent farmland. Similarly think about
how changes in the hydrology of the surrounding catchment might have affected a
fen in the past, or might affect it in future.
7.1.7 Monitoring
Wherever possible, the hydrological effects of a remediation strategy should be
assessed. Monitoring should include characterisation of the baseline (current)
hydrological regime, both pre-implementation and post-implementation. The
duration of monitoring depends on the likely time for the remediation strategy to
take effect. Monitoring of the hydrological effects of installing a sluice to raise
water levels might be possible over several hours, or days, but monitoring might be
required over a much longer period, possibly years, to determine the success or
otherwise of other attempts to restore the desired hydrological regime.
7.2 Lowering the land level
Lowering the land level on fens sometimes happens inadvertently through
subsidence as a consequence of adjacent mining activity or shrinkage of the peat
following hydrological changes. Most deliberate attempts at lowering land level
in relation to the water table are through digging out peat or creating scrapes,
generally in small areas. Old turf ponds (rectilinear features with steep sides and
relatively even depths) were originally dug to provide peat for fuel, whilst scrapes
(with curved, shelving margins and varied topography) have been created to improve
habitat conditions for species such as wading birds and dragonflies.
The cutting of peat for fuel (turbary) was widespread throughout Britain and carried
on well into the mid 19th century in some areas. Most peat-based fens and bogs
have been cut-over, in part at least, including the Cambridgeshire and Lincolnshire
Fens and Somerset Levels. A floating raft of species-rich vegetation developed over
the former turf ponds, dominated by brown mosses and small sedges, with rarities
such as fen orchid (see Section 2: Fen Flora and Fauna). By the late 20th century
dense mats of reed and other wetland plants had replaced this more diverse habitat.
150
A series of three turf ponds
dug to different depths at
Whitlaw Mosses 10 years
ago. The ponds replicate
retting pools that were
used historically to process
flax. The pools were hand
dug and the spoil flattened
by foot in the surrounding
edges to ensure turves
were not colonised by tree
seedlings (D.Brown).